1. Field of the Invention
The present invention relates, in general, to computer networks and, more specifically, to interfaces for interconnecting multiple computers in a network configuration for access to common, stored programs and/or data stored in a memory.
Computer networks, such as a conventional prior art computer network shown in FIG. 1, typically include a number of computers, such as small or personal computers, which are interconnected via common data, address and control signal busses with a common memory comprising hard disks or tapes and shared peripheral I/O devices, such as CRTs and printers. Typically, a memory controller controls the flow of data and control signals between the busses and the memory and peripheral I/O devices.
An interface, such as a small computer system interface (SCSI), connects each peripheral computer to the shared busses to allow access of any individual computer to the common memory and I/O devices. The computer system interface controls the flow of data and control signals between the devices connected to the network.
However, in such computer networks, data communication between the peripheral computers, the computer system interface, the common memory and the peripheral I/O devices is in parallel bytes. Such parallel data transfer places a severe distance restriction on the network which limits the length of the communication busses between the computer system interface and the memory controller. Such distances have been limited to less than 100 feet. Thus, the interface must be physically located in relatively close proximity to the memory, such as within 90 feet. This limits the use of computer networks to those applications where the computer system interface and the memory can be located in such close proximity.
Thus, it would be desirable to provide a computer network expander for a computer network which enables peripheral computers and computer system interfaces to be physically located at considerable distances from a common, shared memory and shared, peripheral I/O devices. It would also be desirable to provide a computer network extender which is simple and inexpensive to add to a computer network. Finally, it would be desirable to provide a computer network extender which does not require modification of the existing peripheral computers, computer system interface, memory or I/O devices.